Many surgical interventions require the accurate insertion and orientation of one or more surgical instruments. For example, in interventional cardiology, this may relate primarily to a insertion and orientation of a catheter or electrical lead, into a tissue region of heart or in the vascular network, in a predetermined trajectory. Pre-operative planning for such procedures conventionally depends upon two-dimensional radiographic images typically in two orthogonal view directions, making it difficult to determine the shape and structure of regions of interest during surgery. Although rudimentary image processing for volumic image reconstruction, region of interest masking and image enhancement techniques can significantly aid interpretation of two dimensional image planes, a significant lapse exists between interpreting functional radiological images seen at the pre-surgical stage and the actual patient anatomical structures at the operating table. Correlation of exact anatomical locations of interest from structurally less accurate (and often skewed) functional image data, such as SPECT, is challenging. Preliminary primary and secondary research as well as information in the literature has indicated that it is not uncommon for biomedical imaging research groups and medical centers to utilize in-house codes as well as advanced commercial face recognition technology (such as those developed by Fuji, Sony, Microsoft, etc.) to fuse structurally accurate computed tomography (CT) or magnetic resonance imaging (MRI) data with information obtained from positron emission tomography (PET), ultrasound and fluoroscopy data. Such co-registration has admittedly increased diagnostic accuracy and specificity during interventional treatments across surgical specialties, including orthopedics, cardiovascular and neurosurgery. However, the ability to introduce these data into the operating room has still been found wanting.
Cardiac resynchronization therapy (CRT), at present, confers no benefit to at least 30% of patients referred for therapy, a significant limitation of this invasive and expensive treatment. Left ventricular lead placement is an important determinant in response to therapy, with CRT conferring optimal benefit when the left ventricle lead is localized to the latest-activating, non-scarred region. At present, left ventricle lead implantation is essentially empiric; that is, performed with limited consideration of the patients' left ventricle scar or mechanical activation features. This is despite the fact that such information is readily available using non-invasive imaging techniques. There exists a need for a method for intra-operatively guiding left ventricle lead implantation.
Another example of a procedure that remains challenging is catheter ablation of ischemic ventricular tachycardia (VT). Common hindrances include the long duration often required to adequately characterize the substrate, as well as pleomorphism and/or hemodynamic intolerance of induced tachycardias. Long duration and lack of predictability conspire to decrease operator enthusiasm for the procedure, relegating it to use primarily in patients who experience inefficacy or toxicities of antiarrhythmic drugs. Antiarrhythmic drug use in typical ablation candidates may not be for the best. VT ablation would benefit by more routinely including an empiric, “anatomic” element, akin to pulmonary vein isolation.
There are a number of state of the art technologies for 3-dimensional electroanatomic mapping systems that are currently used in the clinic. Such systems can primarily be classified into those that: a) are dependent upon impedance measurements between individual catheter electrodes and patches placed on a patient's chest and abdomen; and b) utilize magnetic location technology to provide accurate visualization of the magnetosensor-equipped catheter tips. Extensive studies have also been conducted to compare different available techniques for specific surgeries and the latter magnetic-based three dimensional mapping system has been proven to be superior for time-critical interventions involving fluoroscopy and radiofrequency energy delivery time in comparison with current-based system.
There exists a need for improved imaging and data fusion techniques and a method for introducing this fused data into the operating room. The present invention enables image fusion from multiple medical imaging modalities and allows introduction of the resulting fused data into the operating room, registered against the patient anatomy, in tandem with current surgical navigation technology.